During the course of Starcraft II: Wings of Liberty, Matt exchanges frequently with Jim Raynor. Among matters discussed are tactical strategies for upcoming missions, and seedy nostalgic yet humorous conversations about Horners activities outside his workplace in the Hyperion. For example, during one playful exchange between Raynor and Horner, Raynor reminds Horner that he once won a poker game, without completely understanding what the prize was. To his dismay, he was endowed with the gift of marriage to a 'galactic hooker.' Upon hearing this dialogue, players will unlock a Battle.net achievement confirming that the player has heard this humorous banter.
Even though Matt Horner may, at first, present an icy exterior, he is usually considered to be Raynors faithful right hand man, a loyal yet independent part of Jim Raynors Rebel Terran group. During the Starcraft II campaign, Horner makes many useful and insightful remarks about the players strategy and play style. He is a welcome addition the the Hyperion, and is the sole person Raynor tells everything to without hesitation.